3

69
Cell Phone-based Optometry Solution The Inverse of Shack-Hartmann Vitor Pamplona eyenetra.com

TAGS:

description

d

Transcript of 3

  • Cell Phone-based Optometry Solution

    The Inverse of Shack-Hartmann

    Vitor Pamplonaeyenetra.com

  • Andres Rueda

  • Thermometer for vision

    Collaboration with: Ankit Mohan , Manuel M. Oliveira, Ramesh Raskar

  • Collaboration with: Ankit Mohan , Manuel M. Oliveira, Ramesh Raskar

    Thermometer for vision

  • 6.5 Billion

    people

    4.5B have a

    cell phone

    2B have

    refractive errors

    0.6B have URE

  • Shack-Hartmann Wavefront Sensor

    Expensive; Bulky, Requires trained professionals

    Wavefront aberrometer

    6

  • Shack-Hartmann Wavefront Sensor

    Laser

    Sensor MicrolensArray

    Planar Wavefront

    Spot Diagram

  • Laser

    Sensor

    8

    Displacement = Local Slope

    of the Wavefront

    Spot Diagram

    Shack-Hartmann Wavefront Sensor

  • NETRA = Inverse of Shack-Hartmann

    9

    Spot Diagram on LCD

    Cell Phone Display

    Eye Piece

  • 10

    Spot Diagram on LCD

    Inverse of Shack-HartmannUser interactively creates the Spot Diagram

    Displace 25 points but 3 parameters

  • 11

    Spot Diagram on LCD

    Inverse of Shack-HartmannUser interactively creates the Spot Diagram

    Displace 25 points but 3 parameters

  • Eye

    Relaxed Eye with Myopia

    Blurred point

    Red pointat infinity

    perfect vision

    myopia

    hyperopia

    ~10cminfinity

    Focusing Range

    12

  • Eye

    Relaxed Eye with Myopia

    Distinctimage points

    perfect vision

    myopia

    hyperopia

    ~10cminfinity

    Focusing Range

    Pinholes

    13

    Red pointat infinity

    Scheiner’s Principle

  • Eye

    Relaxed Eye with Myopia

    Virtual red pointat infinity

    perfect vision

    myopia

    hyperopia

    ~10cminfinity

    Focusing Range

    14

    A

    B

    Distinctimage points

    Display

  • Relaxed Eye with Myopia

    A

    B

    perfect vision

    myopia

    hyperopia

    ~10cminfinity

    Focusing Range

    Virtual red pointat finite distance

    Move spots towards each

    other

    Display

    Eye

    15

    Distinctimage points

  • B

    A

    Points overlap

    Relaxed Eye with Myopia

    Display

    perfect vision

    myopia

    hyperopia

    ~10cminfinity

    Focusing Range

    Eye

    Virtual red pointat finite distance

    Move spots towards each

    other

    16

  • B

    A

    Points overlap

    Relaxed Eye with Myopia

    Display

    perfect vision

    myopia

    hyperopia

    ~10cminfinity

    Focusing Range

    Eye

    Virtual red pointat finite distance

    Move spots towards each

    other

    17

    d

  • Points overlap

    Relaxed Eye with Myopia

    perfect vision

    myopia

    hyperopia

    ~10cminfinity

    Focusing Range

    Eye

    18

    d

    d

    1

    Point at infinity

  • Interactive Method

    20

  • Interactive Method

    21

  • Interactive Method

    22

  • Interactive Method

    23

  • Interactive Method

    Farthest Focal Point(myopia, hyperopia, astigmatism) 24

  • Limitations

    • Children

    • Ability to align lines

    • Resolution is a function of the display DPI

    – Samsung Behold II – 160 DPI – 0.35D

    – Google Nexus One – 250 DPI – 0.2D

    – Apple iPhone 4G – 326 DPI – 0.14D

    25

  • Why Now?

    0.35um

  • Confidential 27

    NETRA Prototypes Worldwide29 partners in 14 countries.

  • Clinical Testing Partners

  • NETRA Team at LVPEI, India

  • Kenya

  • Tufts U. (Boston) NETRA vs Manifest Refraction

    -5.00

    -4.00

    -3.00

    -2.00

    -1.00

    0.00

    1.00

    2.00

    3.00

    4.00

    5.00

    -5.00 -3.00 -1.00 1.00 3.00 5.00

    Net

    ra (D

    )

    Retinoscopy (D)

    13 adults

    -7.00

    -5.00

    -3.00

    -1.00

    1.00

    3.00

    5.00

    7.00

    -7.00 -2.00 3.00

    Net

    ra (D

    )

    Retinoscopy (D)

    29 adults

    LVPEI (India)NETRA vs Retinoscopy

    Validation: Side by Side Trials

  • Preventable Blindness

    WHO 2004

  • Unique, quantitative lens mapping

    CATRA: Quantitative Cataract Maps

    with: Erick Passos, Jan Zizka, Everett Lawson, Esteban Clua , Manuel M. Oliveira, Ramesh Raskar

  • Testing the Presence of Cataracts

    34

    Blin

    kin

    g p

    atte

    rns

    on

    Scr

    ee

    n

    Cell Phone Display

    Pinhole

    Lens

  • 36 years old female with Posterior Sub-Capsular (10%)

    CATRA’s Opacity MapSlit-lamp

    Retro-illumination

  • For the Future

    • Ophthalmology for Masses– >.5 billion URE. > 2.5 billion RE. -> Devices for all

    • Quality of phones (resolution) will increase exponentially

    • New features (recently cataracts, next Retinal NETRA)

    • Smart phones will take over the market in developing world countries like India in next 5 years.

    • Hardware store

  • NETRAhttp://eyenetra.com

    Vitor Pamplona

  • Photography in 1960s

    Illana Tamir

    Roboppy

  • Today, cameras are everywhere

    Photo: Derek K. Miller

    Photo: Tyler

    Photo: John Kannenberg

  • Corneal TopographerWavefront Aberrometer

    Phoropter

    Optometry Today

    Snellen chartTrial set of lenses Lasers

  • “point-and-shoot” optometry

  • Traditional User Driven

    Mass-use Devices Scientific Instruments

  • Phoropter

    Snellen chart

    Trial lenses

    Reading Charts

    • Accuracy– Sharpness Estimation is subjective

    – Brightness affects results

    – Pupil size variation and DoF

    • Cost– Trial Lens Set > $150

    – Bulky

  • EHR

    DeliveryDiagnosticEyecare

    Providers

    New Ecosystem

    Asynchronous

    Medical IT Systems

  • Retinoscope w/

    Lenses

    Auto-refracto-

    meter

    Chart with

    Lenses

    In-Focus: Focometer Optiopia

    Solo-health: EyeSite

    NETRA

    Technology Shining Light plus lenses

    FundusCamera

    Moving lenses + target

    Moving lenses + target

    Reading chart on monitor

    Cellphone+ eyepiece

    Cost to buy $2,000* ~$10,000 ~$100 ~$495 ~$200 -- $30

    Cost per test ~$36 ~$36 ~$5 -- -- -- ~$1

    Data capture No Comp. No No No Comp. Phone

    Mobility 10Kg 2kg 1kg 10Kg

  • Human Eye

    Human Eye

    Cornea(~40D) Crystalline lens

    (10~20D)

    Retina

    46

  • Human Eye

    Human Eye

    Cornea(~40D) Crystalline lens

    (10~20D)

    Retina

    47

    Accommodation

  • Infinity

    Perfect Vision System

    Human Eye

    Infinity

    Subject can focusat infinity

    10cm

    Normal Vision

    48

    Accommodation Range

  • Myopia (nearsightedness)

    Infinity

    Subject cannot focusat far distances

    10cm

    Normal Vision

    Myopia

    Wrong focal point

    49

    Accommodation Range

    Infinity

    Human Eye

  • Myopia Correction

    Infinity

    Subject can focusat infinity

    10cm

    Normal Vision

    Myopia

    Divergent Lens

    Corrected Myopia

    50

    Accommodation Range

    Infinity

    Human Eye

  • Hyperopia (farsightedness)

    Infinity 10cm

    Normal Vision

    Myopia

    Hyperopia

    Wrong focal point

    51

    Accommodation Range

    Infinity

    Human Eye

  • Hyperopia Correction

    Infinity

    Accommodation Range

    10cm

    Normal Vision

    Myopia

    Hyperopia

    Convergent Lens

    52

    Corrected Hyperopia

    Infinity

    Human Eye

  • Refractive Errors and Shifted Range

    Perfect vision

    Myopia

    Hyperopia

    10cmInfinity

    Need to measure

    54

    1m 33cm Distance

  • Refractive Errors and Shifted Range

    Perfect vision

    Myopia

    Hyperopia

    10cmInfinity

    55

    -10D0D

    Diopter = 1/Distance

    -3D-1D

    1m 33cm

    +1D+3D

    Distance

    Diopter

  • Astigmatism: angle-dependent refractive error

    http://www.elizabethpope.co.uk/eyeinfo/astigmatism.html 56

  • Astigmatism: angle-dependent refractive error

    http://www.elizabethpope.co.uk/eyeinfo/astigmatism.html 57

  • Astigmatism: angle-dependent refractive error

    http://www.elizabethpope.co.uk/eyeinfo/astigmatism.html 58

  • Refractive Power as a Function of Angle

    59

    Cylinder SphereAxis Cyl.Unknowns:

    SCP )(sin(2

  • Astigmatism

    Cross or points may never meet with a 1d search !60

  • Astigmatism

    Lines reduce the problem to a 1d search61

  • Measuring the Accommodation Range

    62

    Perfect vision

    ~10cmInfinity

    Myopia

    Hyperopia

    Step 1: Far limit Step 2: Near limit

  • Measuring the Accommodation Range

    63

    Perfect vision

    ~10cmInfinity

    Myopia

    Hyperopia

    Step 1: Far limit Step 2: Near limit

  • Measuring the Accommodation Range

    64

    Perfect vision

    ~10cmInfinity

    Myopia

    Hyperopia

    Step 1: Far limit Step 2: Near limit

  • Points overlap

    A

    B

    Display

    Virtual Point at the far limit

    Relaxed Eye

    65

  • Points overlap

    A

    B

    Display

    Accommodated Eye

    66

    Virtual pointgetting closer

    Move points towardseach other

    Subject Accommodates to fix the “blur”

  • Points overlap

    A

    B

    Display

    Accommodated Eye

    67

    Virtual pointgetting closer

    Move points towardseach other

    Subject Accommodates to fix the “blur”

  • Points overlap

    A

    B

    Display

    Accommodated Eye

    68

    Virtual pointgetting closer

    Move points towardseach other

    Subject cannot accommodate more than the previous point

  • Patterns for Alignment Task

    Displayed

    Subject view

    Displayed

    Subject view

    69

    Visual Cryptography

    A B A B A B A B A B

    A B A B A B A B A B

    [NaorShamir94]

  • Patterns for Alignment Task

    Displayed

    Subject view

    Displayed

    Subject view

    70

    Visual Cryptography

    A B A B A B A B

    A B A B A B A B A B

    A B

    [NaorShamir94]

  • Summary of Interaction

    Farthest Point(myopia, hyperopia, astigmatism)

    Nearest Point(presbyopia)

    Accommodation Range

    71